CLEVELAND (CNNMoney.com) -- When homeowners moved away after a wave of foreclosures in Cleveland's working-class neighborhood of Slavic Village, crime took off.

Slavic Village is known as the worst neighborhood in the nation for foreclosures. In a study for CNNMoney, RealtyTrac calculated that properties in its ZIP code recorded more foreclosure filings in three months than anywhere else in the United States.

According to Jim Rokakis, Cuyahoga County Treasurer, more than 800 houses now sit vacant and moldering in the area, which was founded in the 1840s by Polish and Bohemian immigrants who worked in area steel mills and factories.

The first thing that happened after owners moved out of foreclosed homes in Slavic Village was that squatters and looters moved in, according to Mark Wiseman, director of the Cuyahoga County Foreclosure Prevention Program. "In the inner city, it takes about 72 hours for a house to be looted after it is vacant," he said.

Walking around the neighborhood, Mark Seifert, director of the East Side Organizing Project pointed out a home he said was still occupied less than two weeks before. The gutters and downspouts were already gone, and trash covered the yard.

Long-time Slavic Village resident Joe Krasucki had celebrated his 78th birthday last spring, when, late in the evening, he heard some noise and went out for a look. Reports said he'd had run-ins with local gangs before. A neighbor's abandoned house had already been stripped of its aluminum siding and, according to Rokakis, Krasucki thought the looters were back, working on his home. Outside, he was attacked and badly beaten. He died some days later.

After stripping the siding, looters don't take long to make a vacant property nearly worthless.

"If someone takes the doors, moldings, appliances, it's bad enough," said Wiseman. "But once they pull the piping out, it's all over; they do it with a sledge hammer."

Putting a house back together takes money, more money than the restored home could bring on the market. And stopgap programs, such as razing derelict houses, aren't feasible - Cuyahoga County only has a few million dollars available for demolition work, and Wiseman estimates at least $100 million is needed.

Many houses in Slavic Village have had their siding stripped up to the roof lines. A few criminal masterminds even stripped vinyl siding, apparently unaware of the difference in wholesale scrap prices between plastic and metal.

When a house is derelict, people will dump garbage in the yard, rather than pay for haulage. Windows are broken, and doors are stolen, opening up the interior to the elements. In Cleveland's cold and damp climate, the houses deteriorate quickly. But some not badly enough to keep drug dealers out.

Asteve'e "Cookie" Thomas was just 12 years old this past summer when she was gunned down coming out of a Slavic Village candy store, caught in a crossfire from suspected dealers engaged in a drug war. Seifert said one of the alleged shooters was using an abandoned house in the neighborhood as a base.

According to the Cleveland Plain Dealer, five people, including Thomas and Krasucki, have been killed in Slavic Village in the past two years: In July, Grady Smith, 27, was shot outside his home while working on his car. In Nov. 2006, Roman Grasela, 71, died of blows to his head after his house was broken into. And in October 2005, Therese Szelugowski, 76, died weeks after falling and hitting her head after she was mugged.

Some Slavic Village home owners, still hoping to salvage something out of houses they have vacated, have installed stout doors on entryways with thick locks. They board up windows with three-quarter-inch, exterior-grade plywood.

Others attempt to thwart looters by advertising the lack of anything of value inside. They paint signs saying: "No copper, No wiring, PVC."

Residents have tried to fight back, organizing neighborhood watch groups and lobbying the police, who, many feel, are too often missing in action.

Seifert pointed out an open, empty lot on one block that had been used by car thieves for months and months to store and strip parts from stolen cars. It took a concerted effort by a local group called "Bring Back the 70's" (which refers to the street numbers in the neighborhood) to get the police to clear the lot of the thieves.

But as the number of empty lots and abandoned houses grows where houses and residents were once packed in a tight community, there are fewer and fewer neighbors to fight the battle.